Electrical Supply - Trane CXAO Installation Operation & Maintenance

5.2

Electrical supply

The supply voltage of the unit must be equal to that
specifi ed on the rating plate ± 10%, while in voltage
unbalance between phases must not exceed ± 3%.
Measure the voltage between phases and verify that the
measured value is not within the limits.
WARNING! Provide an adequate supply voltage.
Inadequate supply voltage may cause malfunction of
control components and unwanted interventions thermal
protection as well as a substantial reduction of the life of
the contactors and electric motors.
Unbalance in power supply voltage
In a three phase system the excessive unbalance
between the phases is the cause of the overheating of
the engine. The maximum allowed voltage unbalance is
3%, calculated as follows:
Unbalance %: ((V max - V average) / V average) x 100 =
_______%
Unbalance between phases in the power supply
Do not operate the electric motors when the unbalance
voltage between the phases is greater than 3%.
Use the following formula for the control:
% Voltage unbalance = (Max voltage deviation from
average)/(medium voltage)*100
RF-SVX003A-GB
Important!
If the grid voltage has an imbalance greater than 3%,
contact the company for distribution of electricity.
Operating the unit with a bias voltage between phases
over 3% is inhibited or lose the warranty.
Electrical resistances power supply
Each compressor comes with an electrical resistance
located in the compressor's lower area. Its purpose
is to warm the lubricating oil and thus avoid the
transmigration of refrigerant fl uid within. It is therefore
necessary to ensure that the resistances are powered at
least 24 hours before the planned startup time.
To ensure that they are activated, it is suffi cient to keep
the unit on by closing the general disconnecting switch
Q10.
The microprocessor, however, has a series of sensors
that prevent the compressor being started up when
the oil temperature is not at least 5°C above the intake-
pressure equivalent saturation temperature. Keep the
Q0, Q1, Q2 and Q12 switches in the Off (or 0) position
until the unit is to be started up.
Electrical supply
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